Are there any MacBook Pro / Yosemite performance diagnostic tools?

My colleague has this old MacBook Pro (image attached). I had been told it was 'a few years' old, not quite as old as it actually is.

My colleague has upgraded to Yosemite, but is now experiencing massive lag and beachballing even when doing simple actions like select a menu option (the getting of the attached screenshot took approx 10 mins to open system info, screengrab and email).

Does anyone have any suggestions of diagnostic tools that may help alleviate these problems slightly? I appreciate it's always going to run slowly on this older hardware, but any ideas or tips on even the slightest of improvements would be most welcome and appreciated!